src/helper/log.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include "log.h"
  25 #include "configuration.h"
  26 #include "time_support.h"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <stdarg.h>
  32 #include <time.h>
  33
  34 int debug_level = -1;
  35
  36 static FILE* log_output;
  37 static log_callback_t *log_callbacks = NULL;
  38
  39 static long long start;
  40
  41 static char *log_strings[5] =
  42 {
  43         "User:   ",
  44         "Error:  ",
  45         "Warning:",
  46         "Info:   ",
  47         "Debug:  "
  48 };
  49
  50 static int count = 0;
  51
  52 /* The log_puts() serves to somewhat different goals:
  53  *
  54  * - logging
  55  * - feeding low-level info to the user in GDB or Telnet
  56  *
  57  * The latter dictates that strings without newline are not logged, lest there
  58  * will be *MANY log lines when sending one char at the time(e.g.
  59  * target_request.c).
  60  *
  61  */
  62 static void log_puts(enum log_levels level, const char *file, int line, const char *function, const char *string)
  63 {
  64         if (level == LOG_LVL_OUTPUT)
  65         {
  66                 /* do not prepend any headers, just print out what we were given and return */
  67                 fputs(string, log_output);
  68                 fflush(log_output);
  69                 return;
  70         }
  71
  72         char *f = strrchr(file, '/');
  73         if (f != NULL)
  74                 file = f + 1;
  75
  76         if (strchr(string, '\n')!=NULL)
  77         {
  78                 if (debug_level >= LOG_LVL_DEBUG)
  79                 {
  80                         /* print with count and time information */
  81                         int t=(int)(timeval_ms()-start);
  82                         fprintf(log_output, "%s %d %d %s:%d %s(): %s", log_strings[level+1], count, t, file, line, function, string);
  83                 }
  84                 else
  85                 {
  86                         /* do not print count and time */
  87                         fprintf(log_output, "%s %s:%d %s(): %s", log_strings[level+1], file, line, function, string);
  88                 }
  89         } else
  90         {
  91                 /* only entire lines are logged. Otherwise it's
  92                  * single chars intended for the log callbacks. */
  93         }
  94
  95         fflush(log_output);
  96
  97         /* Never forward LOG_LVL_DEBUG, too verbose and they can be found in the log if need be */
  98         if (level <= LOG_LVL_INFO)
  99         {
 100                 log_callback_t *cb, *next;
 101                 cb = log_callbacks;
 102                 /* DANGER!!!! the log callback can remove itself!!!! */
 103                 while (cb)
 104                 {
 105                         next=cb->next;
 106                         cb->fn(cb->priv, file, line, function, string);
 107                         cb=next;
 108                 }
 109         }
 110 }
 111
 112 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 113 {
 114         char *string;
 115
 116         count++;
 117         if (level > debug_level)
 118                 return;
 119
 120         va_list ap;
 121         va_start(ap, format);
 122
 123         string = alloc_vprintf(format, ap);
 124         if (string != NULL)
 125         {
 126                 log_puts(level, file, line, function, string);
 127                 free(string);
 128         }
 129
 130         va_end(ap);
 131 }
 132
 133 void log_printf_lf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 134 {
 135         char *string;
 136
 137         count++;
 138         if (level > debug_level)
 139                 return;
 140
 141         va_list ap;
 142         va_start(ap, format);
 143
 144         string = alloc_vprintf(format, ap);
 145         if (string != NULL)
 146         {
 147                 strcat(string, "\n"); /* alloc_vprintf guaranteed the buffer to be at least one char longer */
 148                 log_puts(level, file, line, function, string);
 149                 free(string);
 150         }
 151
 152         va_end(ap);
 153 }
 154
 155 /* change the current debug level on the fly
 156  * 0: only ERRORS
 157  * 1: + WARNINGS
 158  * 2: + INFORMATIONAL MSGS
 159  * 3: + DEBUG MSGS
 160  */
 161 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 162 {
 163         if (argc == 0)
 164                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 165
 166         if (argc > 0)
 167                 debug_level = strtoul(args[0], NULL, 0);
 168
 169         if (debug_level < 0)
 170                 debug_level = 0;
 171
 172         if (debug_level > 3)
 173                 debug_level = 3;
 174
 175         return ERROR_OK;
 176 }
 177
 178 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 179 {
 180         if (argc == 1)
 181         {
 182                 FILE* file = fopen(args[0], "w");
 183
 184                 if (file)
 185                 {
 186                         log_output = file;
 187                 }
 188         }
 189
 190         return ERROR_OK;
 191 }
 192
 193 int log_register_commands(struct command_context_s *cmd_ctx)
 194 {
 195         start = timeval_ms();
 196         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 197                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 198         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 199                 COMMAND_ANY, "adjust debug level <0-3>");
 200
 201         return ERROR_OK;
 202 }
 203
 204 int log_init(struct command_context_s *cmd_ctx)
 205 {
 206         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 207         if (debug_level == -1)
 208                 debug_level = LOG_LVL_INFO;
 209
 210         if (log_output == NULL)
 211         {
 212                 log_output = stderr;
 213         }
 214
 215         return ERROR_OK;
 216 }
 217
 218 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 219 {
 220         log_output = output;
 221         return ERROR_OK;
 222 }
 223
 224 /* add/remove log callback handler */
 225 int log_add_callback(log_callback_fn fn, void *priv)
 226 {
 227         log_callback_t *cb;
 228
 229         /* prevent the same callback to be registered more than once, just for sure */
 230         for (cb = log_callbacks; cb; cb = cb->next)
 231         {
 232                 if (cb->fn == fn && cb->priv == priv)
 233                         return ERROR_INVALID_ARGUMENTS;
 234         }
 235
 236         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 237         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 238                 return ERROR_BUF_TOO_SMALL;
 239
 240         /* add item to the beginning of the linked list */
 241         cb->fn = fn;
 242         cb->priv = priv;
 243         cb->next = log_callbacks;
 244         log_callbacks = cb;
 245
 246         return ERROR_OK;
 247 }
 248
 249 int log_remove_callback(log_callback_fn fn, void *priv)
 250 {
 251         log_callback_t *cb, **p;
 252
 253         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 254         {
 255                 if (cb->fn == fn && cb->priv == priv)
 256                 {
 257                         *p = cb->next;
 258                         free(cb);
 259                         return ERROR_OK;
 260                 }
 261         }
 262
 263         /* no such item */
 264         return ERROR_INVALID_ARGUMENTS;
 265 }
 266
 267 /* return allocated string w/printf() result */
 268 char *alloc_vprintf(const char *fmt, va_list ap)
 269 {
 270         /* no buffer at the beginning, force realloc to do the job */
 271         char *string = NULL;
 272
 273         /* start with buffer size suitable for typical messages */
 274         int size = 128;
 275
 276         for (;;)
 277         {
 278                 char *t = string;
 279                 string = realloc(string, size);
 280                 if (string == NULL)
 281                 {
 282                         if (t != NULL)
 283                                 free(t);
 284                         return NULL;
 285                 }
 286
 287                 va_list ap_copy;
 288                 va_copy(ap_copy, ap);
 289
 290                 int ret;
 291                 ret = vsnprintf(string, size, fmt, ap_copy);
 292                 /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 293                 if ((ret >= 0) && ((ret + 1) < size))
 294                         break;
 295
 296                 /* there was just enough or not enough space, allocate more in the next round */
 297                 size *= 2; /* double the buffer size */
 298         }
 299
 300         /* the returned buffer is by principle guaranteed to be at least one character longer */
 301         return string;
 302 }
 303
 304 char *alloc_printf(const char *format, ...)
 305 {
 306         char *string;
 307         va_list ap;
 308         va_start(ap, format);
 309         string = alloc_vprintf(format, ap);
 310         va_end(ap);
 311         return string;
 312 }